Heat exchange device



June 5, 1951 c. L. DAUN HEAT EXCHANGE DEVICE Filed May 9, 1946 IN VEN TOR. CARL L. 124 UAL BY l w Affarn 4y N K n k Patented June 5, 1951 UNITED STATES PATENT OFFICE HEAT EXCHANGE DEVICE Carl L. Daun, Milwaukee, Wis.

Application May 9, 1946, Serial No. 668,601

2 Claims. 1

This invention relates to heat exchange devices and more particularly to a device adapted to function to maintain two separate fluids at substantially the same temperature.

The primary object of the present invention resides in the provision of a new and improved heat exchange device comprising a plurality of nested containers adapted respectively to hold different fluids and arranged in a manner which permits a single refrigerant chamber to effectively reduce the temperatures of two separate fluids to a substantially equal temperature.

A further object of the present invention resides in the provision of new and improved means for maintaining two separate fluids at substan tially the same temperature even though they be withdrawn from the unit separatel or simultaneously at varying rates of draw.

A further object of the present invention resides in the provision in a heat exchange device of means adapted to accelerate the refrigerating action on the fluid which is to be withdrawn at the greater rate of draw.

Another object of the present invention resides in the provision of a refrigerated storage space of ample capacity for the fluid which is to be withdrawn at the greater rate.

Another object of the present invention resides in the structural arrangement of the outlets for the two refrigerated fluids which insures their discharge at a substantially uniform and constant temperature.

A more specific object of the invention resides in the provision of a spirally formed fin coopcrating with the refrigerant container and the wall of one of the fluid containers to form a con tinuous narrow passageway for the fluid of the last named container to insure the rapid and ef fective refrigeration of the fluid to compensate for the increased rate of withdrawal of this particular fluid above the rate of withdrawal of the other refrigerated fluid.

Other objects and advantages will become manifest from the following description of an illustrative embodiment of the invention shown in the accompanying drawing.

In the drawing:

Figure 1 is a vertical transverse sectional view taken through a heat exchange device constructed in accordance with the teachings of the present invention;

Fig. 2 is a fragmentary top plan view of the device shown in Figure 1; and

Fig. 3 is an enlarged fragmentary vertical sectional view showing the arrangement of a spirally shaped fin having definite heat exchange prop erties in a manner to delineate a continuous narrow passage for one of the fluids to be refrigerated.

As an illustrative embodiment of the present invention, I have chosen the application of the invention to a unit adapted to dispense a syrup and carbonated water either separately or simul-- taneously but by the very nature of their combination these fluids are drawn either at different rates or varying quantities to produce the desired delectable mixture.

Referring more specifically to Figure 1 of the accompanying drawing, it will be noted that the heat exchange device comprises essentially four separate containers arranged in nested relationship which permits a complete telescopic assembly of the containers into a single unit. The innermost or central container II] is cylindrical in shape and is adapted to serve as a reservoir for one of the fluids to be refrigerated, in the present instance for the syrup. The container H3 is provided with a discharge pipe ll extending downwardly from the center of the bottom of the container. The top of the container H1 is normally closed by the application of a lid or cover l2 which also forms a top for the complete unit. The second or refrigerant container i3 is slightly larger in diameter and greater in depth than the container Iii and hence is adapted to surround it to provide a compartment through which the refrigerant may flow. The refrigerant container is provided with an inlet pipe M depending from the bottom of the container and adapted to surround the discharge pipe ll of the syrup container It] in a manner to permit direct contact of the refrigerant with the wall of the syrup discharge pipe. A refrigerant discharge pipe I5 is connected adjacent the upper end of the refrigerant container l3 which is sealed by the application of a ring it; which is soldered or brazed in position along the upper edges of the containers in and it. A spirally shaped fin ll is secured to the outer wall of the refrigerant container [3 for the purpose of materially increasing the eiiective contact area of the heat exchange surface adapted to contact the second fluid, in the present instance carbonated water. The outer edge of the fin ll is adapted to contact the inner side wall of a container it which is also cylindrical in form and of greater depth than the refrigerant container is so as to provide a reservoir l9 disposed below the bottom surface of the refrigerant container. The carbonated water container I8 is closed at its upper end by the application of a 3 ring 20 which is soldered or brazed to the wall of the container 13 and the upper edge of the container [8. An intake pipe 2| directs the carbonated water into the upper end of the container [8 in a manner which requires that the entire intake of fluid must pass through the elongated passage formed by the spiral fin l'i which cooperates with the wall of the containers l3 and I8 to form a narrow passage which insures the rapid exchange of heat from the water to the refrigerant as the water flows downwardly along the spiral path delineated by the fin it until it is discharged into the reservoir E9 of the container i8. The container !8 is provided with a discharge pipe 22 extending downwardly from the bottom of the container 18 and disposed in a manner to surround the refrigerant intake pipe Hito insure the discharge of the carbonated water at a temperature substantially equal to that of the syrup. The lower extremity of the pipe 22 is provided with a closure plate 23 having a discharge opening 24 adapted to direct the carbonated water through a passage 25 formed in a nipple or casting 26 which is adapted to be secured in any simple manner to the lower extremities of the several pipes II, It and 22. The

carbonated water container i8 is surrounded by a container 21 which is of larger diameter and greater depth than the container it which it surrounds. The space between the containers i8 and 2? is filled with suitable insulating material 28 to prevent heat loss. It should be noted at this time that the lower end of the refrigerant pipe [4 is closed by a ring 29 which is soldered to the pipes M and H. The intake for the refrigerant comprises a pipe 30 Which leads into the pipe Hi through a suitable opening formed near the lower extremity of the pipe i i. The open end of the syrup discharge pipe H directs the syrup into a passage 3! also formed in the nipple 26. The passages 25 and 3! direct the carbonated water and syrup to a spigot or mixing valve- 32 which is under manual control through the medium of an operating knob 33.

A brief description of the operation of the heat exchange device will suflice to emphasize the numerous advantages of the device. With the refrigerant inlet and outlet pipes 39 and I respectively connected in the conventional manner to a suitable compressor, it is possible to circulate a refrigerant through the space between the inner wall of container l3 and the outer wall of container iii. The desired syrup may be placed in the container i8 and the carbonated Water intake pipe 2| may be connected to the usual source to charge the container is with a fluid to be refrigerated to the same temperature as that of the syrup contained in the chamber Iii. In the operation of the present unit it is to be understood that the volume of syrup drawn from the container i9 is considerably less that the volume of carbonated water drawn from the container it. In view of this condition, it is necessary to provide a means which is effective to accelerate the refrigerating of the fluid which is withdrawn in greater volume. This mode of operation has been successfully accomplished by the inclusion of the means for exposing the carbonated water in minute quantities to the entire surface of the spiral fin I? which has excellent heat exchange properties. The refrigerated carbonated water is discharged from direct contact with the continuous narrow passage into the reservoir l9 disposed at the bottom of the container [8. The

action of the refrigerant upon the carbonated water in the reservoir 49 continues by its contact with the outer surface of the refrigerant intake pipe It and also with the bottom surface of the refrigerant chamber i-i. By reason of the structure of the present unit gradual absorption of heat at the bottom of. the reservoir ['9 will cause rising currents of warming liquid. These rising currents of warming liquid will contact the bottom surface of the refrigerant container [3 and be promptly cooled and consequently descend again in the reservoir It, thus creating pronounced convection currents which will materially aid in maintaining the supply of carbonated water at the desired temperature.

Since the volume of fluid or syrup in the chamber it is withdrawn in smaller quantities this fluid acts as a holdover during off-cycles of the compressor and thus retains or reduces the temperature of the carbonated water through conduction and convection through contact with the refrigerant chamber. By the same token, when the supply of syrup in the chamber it is replenished with a comparatively large amount of fluid, the cooled carbonated Water will materially accelerate the cooling of the syrup since both the syrup and carbonated water chambers are in direct contact with the refrigerant chamber.

From the above detailed description of the present invention, it will be noted that a new and improved heat exchange device has been provided which will be effective to refrigerate two separate fluids to a substantially equal temperature and maintain them at an equal temperature in spite of the fact that they may be withdrawn from the unit at different rates.

While the invention has been described in considerable detail in the foregoing specification, it is to be understood that various changes may be made in its embodiment without departing from or sacrificing any of the advantages hereinafter claimed.

I claim:

1. A heat exchange device for maintaining two separate fluids at substantially the same temperature, said device comprising an inner container for one of the fluids to be refrigerated, an outer container for the other of the fluids to be refrigerated, and an intermediate container for a refrigerant, said intermediate container being shorter than said outer container and cooperating therewith to delineate a reservoir portion at the bottom of said outer container, a spiral fin disposed between the outer surface of said refrigerant container and the inner surface of said outer container, said fin serving to form a relatively long channel of small cross sectional area through which said fluid must pass in direct contact with the heat exchange surfaces of said fin and the outer wall of said refrigerant container, said channel discharging into said reservoir portion of said outer container the upper wall of which comprises the bottom of said intermediate refrigerant container, and inlet and outlet means for the fluid of each of said containers.

2. A heat exchange device for maintaining two separate fluids at substantially the same temperature, said device comprising a plurality of nested containers including an inner container for one of said fluids to be refrigerated, an Outer sealed container for the other of the fluids to be refrigerated, and an intermediate sealed container for a refrigerant, said intermediate container being shorter than said outer container and cooperating therewith to delineate a reservoir portion at the bottom of said outer container, said refrigerant container having its inner wall delineating said inner container and having its outer wall delineating the inner wall of said outer container, a spiral fin disposed between the inner and outer wall of said outer container and adapted to delineate a relatively long channel of small cross sectional area through which the fluid of said container must pass in direct contact with the heat exchange surfaces of said fin and the outer wall of said refrigerant container, said channel discharging into said reservoir portion of said outer container, and inlet and outlet means for the fluid in each of said containers, said refrigerant inlet means being disposed to REFERENCES CITED 'The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,958,098 ONeil et al Octj. 20, 1936 2,071,188 White Feb.j16, 1937 2,267,819 Di Pietro Dec. 30, 1941 

